You might have not installed Xcode on your system prior to installing Python-Devel. Try installing Xcode first and then refer here in order to do so on your MAC OS X. @user77005
– Prerna JainSep 15 '15 at 5:13

Why 2.7 and not Python 3? And since Python is free software, you can always compile it from its source code...
– Basile StarynkevitchSep 15 '15 at 5:13